This invention relates to tools, and more particularly to motorcycle tire changers. Specifically, it relates to such tire changers as are manually operated. The earliest commercially produced vehicle tires were simple in construction. Tires have become increasingly complex over time with the introduction of tubeless tires with new compounds and belting materials. These changes resulted in stiffer tire sidewalls that greatly resist the stretching of sidewalls required for the mounting and demounting of tires.
The earliest tires could easily be mounted on wheel rims using simple levers commonly referred to as spoons. Many improvements have been made to the tire changing tools art, but most have been focused on the larger market of car and truck tires and wheels which are significantly different than motorcycle tires and wheels. The vast majority of existing tools available for changing tubeless motor vehicle tires may be categorized within three basic technologies.
The first and original category is the tire iron, often referred to as a spoon. Tire irons are simple bars used manually as a lever to urge a tire wall over a tire rim. Mounting and demounting tubeless tires using tire irons is a very difficult and time-consuming task that can easily damage tires and wheels.
The second category of tool is the tire-changing pedestal that locks a wheel horizontally onto a base so that a mounting/demounting lever can be rotated around the rim to separate the old tire and install the new tire. A variation on this tire changing pedestal is a system that locks onto the tire rim and spins the tire while an external fixed mounting/demounting lever removes the old tire and installs the new tire. The tire changing pedestals must be firmly attached to a floor or solid surface by bolts or similar means, and require a significant amount of space for operation. Tire changing pedestals have the advantage of firmly holding a wheel in place while performing the tire changing operation; however the heavy weight of these systems makes them difficult to install or move. They also require over 25 square feet of floor space for convenient operation. The large size and heavy weight of tire changing pedestals makes them too bulky and expensive to be practical for most non-commercial applications.
A third category of the technology which includes the present invention falls between the previously mentioned technologies. This third category involves manually operated tools that either require the wheel to be mounted a on a base plate or frame or require that an axle or spindle be inserted into the wheel hub to act as a fulcrum against which mount/demount arms may be rotated to mount or dismount a tire.
Previous attempts to address the need for a manual tire mount/demount mechanism are represented by patent publication number US 2003/0066613 A1 dated Apr. 10, 2003, U.S. Pat. No. 5,740,848 dated Apr. 21, 1998, U.S. Pat. No. 3,818,967 dated Jun. 25, 1974 and U.S. Pat. No. 3,818,967 dated December 2009.
Patent 2003/0066613 A1 has the disadvantages that it requires that a wheel be affixed to a base plate, that a drive mechanism be provided, and that a separate receiver be provided for a bead rolling tool, and it does not provide a mechanism for balancing wheels.
U.S. Pat. No. 5,740,848 has the disadvantages that it requires that a wheel be fitted with a tire rim engager comprised of a disc and a detachable ring for fitting the tool to a wheel, it does not provide a wheel holding mechanism for countering the force of the mount/demount lever and therefore requires an additional force to hold the wheel in place, and it does not provide a device for balancing wheels.
U.S. Pat. No. 3,818,967 claims that “[S]ubstantially balanced, opposite rotational forces” make the invention self stabilizing but does not provide a wheel holding mechanism for countering the force of the cranking handle therefore it requires an additional force to hold the wheel in place, it introduces a second counter rotating tool head arm which increases resistance relative to a single tool head of conventional tire mounting devices, and it does not provide a device for balancing wheels.
U.S. Pat. No. 7,628,193 claims a tire mounting device composed of a base, a centerpiece, and a class 1 primary lever movable relative to the centerpiece. It is an adaptation of a traditional pedestal mounted tire changer. It utilizes a class 1 lever as a separate moving part. Operation of the primary lever requires application of force on said lever at a distance from the center of the wheel greater than the radius of the wheel and tire combined, the force must be applied on said lever at 360 degrees to the center of the wheel on the plane of the wheel, and simultaneous force must be applied down toward the base of the device. Said application of force would not be feasible if the device were wall mounted. This device has the disadvantage that the centerpiece claimed would not be suitable for use with bearings mounted on the outside of the hub such as motorcycle wheels because the forces applied would cause serious damage to the bearings. This device also has the disadvantage that it does not provide device for balancing wheels as an integrated feature of the design.